Defoaming Compositions

Abstract

Cement compositions and processes for reducing air entrainment in a cement composition generally include mixing a hydraulic cement with a defoamer compositions including one or more organic acid ester polymers selected from an organic acid ester of polyethylene oxide polymer, an organic acid ester of polypropylene oxide polymer, and a mixture thereof. The compositions may further comprise an organic acid ester of an ethylene oxide-propylene oxide block copolymer.

1 - 13 . (canceled) 
     
     
         14 . A method for reducing air entrainment in a cement composition, the method comprising:
 adding a defoaming composition to a cement composition wherein the defoaming composition comprises one or more organic acid ester polymers selected from an organic acid ester of polyethylene oxide polymer, an organic acid ester of polypropylene oxide polymer, and a mixture thereof;   wherein the air entrainment in the cement composition is reduced relative to a cement composition without the defoaming composition.   
     
     
         15 . The method of  claim 14 , wherein the defoaming composition further comprises an organic acid ester of an ethylene oxide propylene oxide block copolymer 
     
     
         16 . The method of  claim 14 , wherein the defoaming composition is added to the cement composition at 0.01 to 1% by weight of the cement. 
     
     
         17 . A cement composition comprising:
 hydraulic cement;   water; and   a defoaming composition comprises one or more organic acid ester polymers selected from an organic acid ester of polyethylene oxide polymer, an organic acid ester of polypropylene oxide polymer, and a mixture thereof.   
     
     
         18 . The cement composition of  claim 17 , wherein the defoaming composition further comprises an organic acid ester of an ethylene oxide propylene oxide block copolymer. 
     
     
         19 . The cement composition of  claim 17 , wherein the hydraulic cement comprises hydraulic cements comprising calcium, aluminum, silicon, oxygen and/or sulfur; Portland cements such as class A, B, C, G, and H cements according to American Petroleum Institute (API) specification for materials and testing for well cements; pozzolana cements; gypsum cements; phosphate cements; high alumina content cements; slag cements; cement kiln dust; silica cements; high alkalinity cements; and combinations comprising at least one of the foregoing cements. 
     
     
         20 . A method of cementing a subterranean formation, the method comprising:
 displacing a cement composition into the subterranean formation, the cement composition comprising hydraulic cement, water, and a defoaming composition comprises one or more organic acid ester polymers selected from an organic acid ester of polyethylene oxide polymer, an organic acid ester of polypropylene oxide polymer, and a mixture thereof; and   allowing the cement to set.   
     
     
         21 . The method of  claim 20 , wherein the defoaming composition further comprises an organic acid ester of an ethylene oxide propylene oxide block copolymer. 
     
     
         22 . The method of  claim 20 , wherein displacing the cement composition comprises pumping the cement composition into an annular space between the walls of a well bore and casing during a primary of a remedial cementing operation. 
     
     
         23 . The method of  claim 20 , wherein the hydraulic cement is foamed and the defoaming composition is added to the hydraulic cement in an amount effective to break the foam, thereby reducing gas entrainment in the hydraulic cement. 
     
     
         24 . The method of  claim 20 , wherein the defoaming composition is at 0.01 to 1% weight of the hydraulic cement.